Plug connectors of this type are known by way of example from the following publications: EP 0 591 947 A2, DE 195 34 205 C2, DE 195 00 959 C2.
Such a plug connector has a tightly limited overall size (for example, length: 2 to 3 cm; width: approx. 1 cm; height: 0.1 to 1.0 cm). It follows from this that individual components of the plug connector and of the associated receptacle must be extremely small in size, though nevertheless in connection with the safety application (for example belt tensioner, airbag) easy assembly on the one hand and high functional reliability on the other hand are required.
This applies in particular with reference to a latching of plug and receptacle, with the contact elements of the components having to contact reliably in the locked state. In like manner, the plug and receptacle must not release from each other unintentionally.
With the aforementioned state of the art, this problem is solved in that the plug and the receptacle in a first work step are contacted and latched together and in a second work step a locking element is brought behind the catch arm of the plug as a so-called secondary locking in order to ensure latching against unintended release.
In the case of the plug connector according to DE 198 40 726 C2, the locking element can be preassembled, and in the preassembled starting position it lies in an elevated position against the effect of a spring. The plug connector and the receptacle can be latched against the effect of the spring.